Greywander
2020-12-20, 08:48 PM
So one of the classes that has been sitting unfinished in my homebrew folder is a sci-fi-esque monstrosity that is able to incorporate the body parts of other creatures into its own, gaining their abilities. I thought it might be interesting to use hit dice to fuel its class features, with the ability to regain hit dice by killing and eating creatures (not necessarily in that order). If you're familiar with homebrew design, then you can probably see the glaring pitfall here: the bag of rats problem.
For those who aren't familiar with it, the bag of rats is an exploit where you have some sort of ability that is triggered by killing something, and you bring a large amount of portable and easily killable creatures with you (such as a bag of rats) to trigger that ability. For example, you might have a vampiric ability that allows you to regain HP every time you kill something, so to heal yourself you just kill a bunch of rats from your bag. Fortunately, 5e doesn't seem to have a lot of abilities that fall foul of the bag of rats exploit.
I should also mention that a bag of rats doesn't need to literally be a bag of rats. It could be any type of creature that you bring with you to trigger this ability.
The question then is, how far do you need to go to curb this exploit? If you have an ability that triggers off of killing (or, in this case, eating) a creature, how many limitations and restrictions do you need before the exploit becomes more trouble than it's worth? I have a few ideas on how to limit this ability that should, hopefully, deal with this bag of rats.
Size
In the given context, it makes sense that you'd need to eat a Small or larger creature to regain HD; Tiny creatures just don't have enough biomass to make a noticeable difference. For example, I could see making a small creature worth 1 hit die, a medium creature worth 2, a large creature worth 4, etc. What this does is make your "bag of rats" more like a "herd of goats". Small creatures are a lot less portable than tiny ones. And they need to be protected, fed, cared for, etc.
Time
Some of the bag of rats exploits seem to take advantage of the action economy: if you have some way of killing an arbitrary number of rats on your turn, and therefore trigger the ability an arbitrary number of times, you can really go nuts and do some insane things in the space of a single round. One way to deal with this is to increase the time required to "kill" the rat and/or activate the ability. In this case, eating isn't instantaneous, especially for person-sized chunks of meat. If eating one hit die's worth of biomass takes even just a minute, it basically prevents any usage in combat.
Freshness
Transporting live animals is hard. Transporting dead ones is much easier. Not to mention all the corpses you're sure to come across during your adventures. It sure would be a shame if there was some sort of time limit after something died during which you had to consume it to gain any benefits, and anything older than that gave you nothing. I'm looking at 24 hours, which should be long enough that you don't need to rush to gobble down your foes as soon as combat ends, but short enough that you still need to worry about keeping your bag of rats alive.
Is this enough? Or do I need to go further? I feel like there's a good chance you'll be able to refresh yourself back to full between fights, so I should probably treat this class like a short rest class. There are some other restrictions we could use, but I'm not sure I want to implement them in this specific case.
Creature Type
In my case, constructs are obviously out. But you could get more specific. If you eliminate beasts, then you remove the most plentiful and least morally objectionable type of creatures from availability. If you restrict it to humanoids, specifically, then you reach that sweet spot where they're plentiful enough to trigger your ability regularly (without the bag of rats), but difficult to transport as a bag of rats, and morally objectionable enough that your party members might not be comfortable with you doing so.
Frequency
A good way to quickly and easily curb the bag of rats is to limit the ability to only trigger a certain number of times per short and/or long rest. It's effective, it's boring, and it doesn't always make sense depending on the ability. Still debating if I should use this or not.
CR or Stats
If the ability specifically requires you to kill even just a creature of CR 1 or higher, then it eliminates all of the best candidates to be your rats, including things like commoners or goblins. Higher CR monsters are more difficult to handle and contain, not to mention kill, and a bag of rats could become a liability that might turn on you. You could also/instead require a certain number of hit dice, or an ability score of a specific value or higher (e.g. INT of 7 or higher if you want only sapient creatures to work), or a certain number of max HP.
What are some other limitations I could use? It's also important to remember that the ability still needs to be fun to use, so it shouldn't be nerfed too heavily. It should be sufficient to make an exploit inconvenient, rather than impossible.
For those who aren't familiar with it, the bag of rats is an exploit where you have some sort of ability that is triggered by killing something, and you bring a large amount of portable and easily killable creatures with you (such as a bag of rats) to trigger that ability. For example, you might have a vampiric ability that allows you to regain HP every time you kill something, so to heal yourself you just kill a bunch of rats from your bag. Fortunately, 5e doesn't seem to have a lot of abilities that fall foul of the bag of rats exploit.
I should also mention that a bag of rats doesn't need to literally be a bag of rats. It could be any type of creature that you bring with you to trigger this ability.
The question then is, how far do you need to go to curb this exploit? If you have an ability that triggers off of killing (or, in this case, eating) a creature, how many limitations and restrictions do you need before the exploit becomes more trouble than it's worth? I have a few ideas on how to limit this ability that should, hopefully, deal with this bag of rats.
Size
In the given context, it makes sense that you'd need to eat a Small or larger creature to regain HD; Tiny creatures just don't have enough biomass to make a noticeable difference. For example, I could see making a small creature worth 1 hit die, a medium creature worth 2, a large creature worth 4, etc. What this does is make your "bag of rats" more like a "herd of goats". Small creatures are a lot less portable than tiny ones. And they need to be protected, fed, cared for, etc.
Time
Some of the bag of rats exploits seem to take advantage of the action economy: if you have some way of killing an arbitrary number of rats on your turn, and therefore trigger the ability an arbitrary number of times, you can really go nuts and do some insane things in the space of a single round. One way to deal with this is to increase the time required to "kill" the rat and/or activate the ability. In this case, eating isn't instantaneous, especially for person-sized chunks of meat. If eating one hit die's worth of biomass takes even just a minute, it basically prevents any usage in combat.
Freshness
Transporting live animals is hard. Transporting dead ones is much easier. Not to mention all the corpses you're sure to come across during your adventures. It sure would be a shame if there was some sort of time limit after something died during which you had to consume it to gain any benefits, and anything older than that gave you nothing. I'm looking at 24 hours, which should be long enough that you don't need to rush to gobble down your foes as soon as combat ends, but short enough that you still need to worry about keeping your bag of rats alive.
Is this enough? Or do I need to go further? I feel like there's a good chance you'll be able to refresh yourself back to full between fights, so I should probably treat this class like a short rest class. There are some other restrictions we could use, but I'm not sure I want to implement them in this specific case.
Creature Type
In my case, constructs are obviously out. But you could get more specific. If you eliminate beasts, then you remove the most plentiful and least morally objectionable type of creatures from availability. If you restrict it to humanoids, specifically, then you reach that sweet spot where they're plentiful enough to trigger your ability regularly (without the bag of rats), but difficult to transport as a bag of rats, and morally objectionable enough that your party members might not be comfortable with you doing so.
Frequency
A good way to quickly and easily curb the bag of rats is to limit the ability to only trigger a certain number of times per short and/or long rest. It's effective, it's boring, and it doesn't always make sense depending on the ability. Still debating if I should use this or not.
CR or Stats
If the ability specifically requires you to kill even just a creature of CR 1 or higher, then it eliminates all of the best candidates to be your rats, including things like commoners or goblins. Higher CR monsters are more difficult to handle and contain, not to mention kill, and a bag of rats could become a liability that might turn on you. You could also/instead require a certain number of hit dice, or an ability score of a specific value or higher (e.g. INT of 7 or higher if you want only sapient creatures to work), or a certain number of max HP.
What are some other limitations I could use? It's also important to remember that the ability still needs to be fun to use, so it shouldn't be nerfed too heavily. It should be sufficient to make an exploit inconvenient, rather than impossible.